WO2011118199A1

WO2011118199A1 - Display switching device

Info

Publication number: WO2011118199A1
Application number: PCT/JP2011/001672
Authority: WO
Inventors: 和俊柏本
Original assignee: パナソニック株式会社
Priority date: 2010-03-24
Filing date: 2011-03-22
Publication date: 2011-09-29
Also published as: US8810588B2; JP5662418B2; JPWO2011118199A1; US20120062573A1

Abstract

Provided is a display switching device such that frame dropping and delay in displaying a frame image are reduced. An image processing terminal (1) is provided with a first drawing component (61) which generates an image for each first time interval and writes said image into a buffer, a second drawing component (62) which generates an image for each second time interval and writes said image into a buffer, a buffer management unit (11) which secures a high-speed frame buffer (31) on a high-speed memory device (18) and which secures a universal frame buffer (32) on a universal memory device (19), and a display switching device (12), wherein the display switching device (12) comprises a switching determination unit (81) which repeatedly calculates the drawing processing load for each drawing component, and a switching execution unit (82) which mutually switches the buffer allocated to each drawing component when the high-speed frame buffer (31) is not allocated to the drawing component having the higher drawing processing load.

Description

Display switching device

The present invention relates to a display switching device in an information processing terminal that displays a plurality of images in a superimposed manner, and particularly to switching control of a plurality of buffers for recording images.

In recent years, in an information processing terminal that displays an image on a display such as a car navigation system or a mobile phone, a plurality of images are displayed in an overlapping manner. For example, in a car navigation system, a case in which a photographic image taken at one point on the map is displayed on a map image is displayed. And since drawing processing is becoming more complex, in addition to general-purpose buffers, information processing terminals are equipped with high-speed buffers that are more expensive and capable of high-speed processing than general-purpose buffers. Time is being shortened. In the case of the car navigation system, a high-speed buffer is assigned to a component that generates a map image displayed on a full display, and a general-purpose buffer is assigned to another component that generates a photographic image. Here, the component corresponds to a component obtained by dividing the application into functions, processes, and the like. If the drawing processing time is extended, frame dropping, frame image display delay, and the like occur, and image display quality deteriorates.

JP 2000-206953 A

By the way, in the information processing terminal, the required drawing process is becoming more complicated. For example, the display of a photographic image in the above-described car navigation system is not limited to simply displaying a photographic image taken at one point on the map, but is enlarged after displaying the photograph at one point in 3D (three-dimensional). It is possible to consider an aspect such as. In this case, the drawing processing time for a photographic image having a smaller display area than the map image temporarily exceeds the drawing processing time for the map image.

If the drawing process becomes complicated as described above, the drawing process time becomes longer, and problems such as frame dropping and frame image display delay become remarkable.

SUMMARY OF THE INVENTION In view of the above problems, an object of the present invention is to provide a display switching device that shortens the drawing processing time compared to the prior art, and reduces frame dropping due to a longer drawing processing time, display delay of frame images, and the like. .

In order to solve the above problems, a display switching device according to an embodiment of the present invention is a display switching device that switches a buffer assigned to each of a plurality of drawing components for a high-speed buffer and a general-purpose buffer for drawing an image, A switching determination unit that repeatedly calculates a drawing processing load for each of a plurality of drawing components, and each time the drawing processing load is calculated, the high-speed one that has the highest drawing processing load calculated among the plurality of drawing components Switch whether to switch the buffer to be assigned to the drawing component with the highest drawing processing load calculated and to the drawing component to which the high-speed buffer is assigned when it is determined whether or not a buffer is assigned. A part.

Since the display switching device according to an embodiment of the present invention has the above-described configuration, the total drawing processing time of the first and second drawing components is shortened after the buffer is replaced. Frame dropping, display delay of frame images, and the like can be reduced.

The block diagram which shows an example of a structure of the information processing terminal provided with the display switching apparatus in Embodiment 1 of this invention The flowchart which shows an example of the flow of the switching judgment processing of the display switching apparatus in Embodiment 1 of this invention. The block diagram which shows an example of a structure of the information processing terminal provided with the display switching apparatus in Embodiment 2 of this invention. The flowchart which shows an example of the flow of the display time calculation process of the display switching apparatus in Embodiment 2 of this invention. Timing chart showing drawing processing for second switching procedure in embodiment 2 of the present invention Timing chart showing drawing processing for fourth switching procedure in embodiment 2 of the present invention Timing chart showing drawing processing for first switching procedure according to Embodiment 2 of the present invention Timing chart showing drawing processing for the third switching procedure in the second embodiment of the present invention The figure which shows an example of the calculated score in Embodiment 2 of this invention The flowchart which shows an example of the flow of the switching procedure selection process in Embodiment 2 of this invention. The flowchart which shows an example of the flow of the switching determination process in Embodiment 2 of this invention.

The display switching device according to claim 1 is a display switching device that switches a buffer assigned to each of a plurality of drawing components for a high-speed buffer and a general-purpose buffer for drawing an image, the display switching device for each of the plurality of drawing components A switching determination unit that repeatedly calculates a drawing processing load, and each time the drawing processing load is calculated, whether or not the high-speed buffer is allocated to the highest drawing processing load calculated among the plurality of drawing components A switching execution unit that switches a buffer to be assigned to the drawing component having the highest drawing processing load calculated and the drawing component to which the high-speed buffer is assigned.

The drawing processing load is a time during which each drawing component performs a drawing process per unit time, and the switching execution unit assumes that the drawing processing load is the highest among the plurality of drawing components. It is also possible to select the one having the longest drawing process per hour.

According to this configuration, the calculation of the drawing processing load can be determined based on the drawing processing time that is relatively easy to measure than the load measurement.

In addition, the switching execution unit includes a first switching procedure for switching a buffer without copying the contents recorded in the high-speed buffer and the general-purpose buffer, and the contents stored in the high-speed buffer in the general-purpose buffer. It is also possible to select one of a second switching procedure for switching the buffer after copying, and a third switching procedure for switching the buffer after copying the contents stored in the general-purpose buffer to the high-speed buffer. Good.

According to this configuration, the buffer switching procedure can be selected from a plurality of procedures. By selecting an optimal procedure, it is possible to minimize the processing loss in the drawing processing after the buffer switching.

In addition, when the switching execution unit selects the one switching procedure, the buffer switching cost for each of the switching procedures is compared with the case where the rendering process is continued without switching the buffer after switching the buffer. It is also possible to estimate and select the procedure with the minimum buffer switching cost.

According to this configuration, it is possible to minimize the processing loss in the drawing processing after the buffer switching.

The buffer switching cost may be determined based on at least one of the number of dropped frames, the number of display delays, and the CPU load value.

According to this configuration, at least one of frame dropping, display delay, and CPU load can be reduced as compared with the conventional case.

The buffer switching cost may be determined based on a value obtained by adding two or more of the number of dropped frames, the number of display delays, and the CPU load value.

According to this configuration, it is possible to determine the number of processing failures after buffer switching only by adding two or more of the number of dropped frames, the number of display delays, and the CPU load value.

In addition, when the frame image is displayed on the screen, the switching execution unit may lock the display without changing the screen display for a period when there is a processing failure when it is determined that there is a processing failure.

This configuration can suppress screen display disturbance.

The display switching method according to claim 8 is a display switching method used for a display switching device that switches a buffer to be assigned to each of a plurality of drawing components for a high-speed buffer and a general-purpose buffer for drawing an image. A switching determination step of repeatedly calculating a drawing processing load for each of the drawing components, and each time the drawing processing load is calculated, the high-speed buffer is assigned to the one having the highest drawing processing load calculated among the plurality of drawing components. Switching step of switching the buffer to be assigned to the drawing component having the highest drawing processing load calculated and the drawing component to which the high-speed buffer is assigned, if it is not assigned. Including.

The integrated circuit according to claim 9 is an integrated circuit that switches a buffer assigned to each of a plurality of drawing components for a high-speed buffer and a general-purpose buffer for drawing an image, wherein the drawing processing for each of the plurality of drawing components A switching determination unit that repeatedly calculates a load, and each time the drawing processing load is calculated, a determination is made as to whether or not the high-speed buffer is allocated to the highest drawing processing load calculated among the plurality of drawing components. And a switching execution unit that switches a buffer to be assigned to the drawing component having the highest drawing processing load calculated and the drawing component to which the high-speed buffer is assigned when the assignment is not made.

According to this configuration, after the buffer is replaced, the total drawing processing time of the first and second drawing components is shortened, so that frame dropping, frame image display delay, and the like can be reduced as compared with the conventional case. .

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

1. Embodiment 1
An information processing terminal 1 including a display switching device according to an embodiment of the present invention is a portable information processing terminal including a touch panel display. As an example, the information processing terminal 1 executes an application that performs navigation for displaying the current position of the information processing terminal 1 on a map image. This application includes a component in charge of displaying a map image (hereinafter referred to as a first drawing component) and a component in charge of a function of displaying a photo (hereinafter referred to as a second drawing component). On the map image, an image generated by each drawing component is superimposed and displayed as necessary, for example, a photographic image obtained by photographing an actual landscape at one point on the map is displayed.

Normally, each time the user holding the information processing terminal 1 moves, the current position of the information processing terminal 1 moves, so that the map image displayed on the display is continuously updated. At this time, the first drawing component that displays a map image has a larger processing load for image processing or the like than the second drawing component that displays a photo. Here, the information processing terminal 1 has two types of memory devices, a high-speed memory device capable of high-speed data processing and a general-purpose memory device, and the high-speed memory device is assigned to the first drawing component.

However, when the user instructs an operation such as enlarging, reducing, and partially displaying a photographic image displayed on the map image, the processing load of the second drawing component is the first. Exceeds the processing load of drawing components. At this time, the display switching device in the information processing terminal 1 replaces the memory device used by the first drawing component and the memory device used by the second drawing component so that the higher processing load uses the high-speed memory device. Control.

Hereinafter, the configuration and processing procedure for appropriately switching the memory device (buffer) that uses each drawing component will be described.

1.1. Configuration Specifically, an information processing terminal 1 according to an embodiment of the present invention includes a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), a touch panel display unit, and a keypad. It is a computer system composed of A computer program is stored in the ROM, and the information processing terminal 1 achieves its function by the CPU operating in accordance with the computer program read onto the RAM.

FIG. 1 is a block diagram schematically showing the configuration of the information processing terminal 1.

In FIG. 1, the information processing terminal 1 is divided into a software part corresponding to the above-described computer program and a hardware part. The software unit includes a frame buffer management unit 11, a display switching unit 21, an application unit 13, and a composition management unit 14. The hardware unit includes a display unit 15, an input unit 16, an information storage unit 17, a high-speed memory device 18, and a general purpose. A memory device 19 and a display memory device 113 are included. Here, the display switching unit 21 and the information storage unit 17 constitute the display switching device 12.
Hereinafter, each configuration will be described in detail.

(1) Hardware Unit The high-speed memory device 18 and the general-purpose memory device 19 are memory devices that hold image data. The high-speed memory device 18 can input and output data at a higher speed than the general-purpose memory device 19. A high-speed frame buffer 31 that is a frame buffer for high-speed drawing processing is secured on the high-speed memory device 18. On the general-purpose memory device 19, a general-purpose frame buffer 32, which is a frame buffer for normal drawing processing, is secured. When the drawing process is performed using the general-purpose frame buffer 32, the load on the CPU or the like is larger than when the same process is performed using the high-speed frame buffer 31.

The display memory device 20 is an image memory. On the display memory device 20, a display buffer 33 for holding an image that is a source of video displayed on the display is secured.

The display unit 15 includes a display control unit 34 and a display 35.

The display 35 is a device that displays an image, and specifically, a liquid crystal display.

The display control unit 34 reads out an image represented by the image data held in the display buffer 33 at every predetermined periodic refresh timing, and displays the image on the display 35.

In response to the information acquisition request, the display control unit 34 notifies display information 46 including refresh interval information indicating the refresh timing interval and refresh time information indicating the time of the most recent refresh.

The input unit 16 includes a keypad and a touch panel. The input unit 16 detects user operations performed using the keypad and the touch panel, and displays key input information representing the input user operations and touch panel operation information (hereinafter referred to as key input information and touch panel operation information). The application unit 13 is notified.

The information storage unit 17 is a secure memory device that holds information. The information storage unit 17 stores information such as first drawing performance information 41, second drawing performance information 42, first frame buffer information 43, and second frame buffer information 44.

The first frame buffer information 43 is information that coincides with either the start address of the high-speed frame buffer 31 or the start address of the general-purpose frame buffer 32.

The content of the first frame buffer information 43 is appropriately rewritten by the display switching unit 21. Therefore, the first frame buffer information 43 coincides with the start address of the high-speed frame buffer 31 at one time, and coincides with the start address of the general-purpose frame buffer 32 at another time. The second frame buffer information 44 is the same as the first frame buffer information. Here, the display switching unit 21 rewrites the contents of the first frame buffer information 43 and the second frame buffer information 44 so as to have a complementary relationship. That is, when the content of the first frame buffer information 43 is matched with the head address of the high-speed frame buffer 31, the content of the second frame buffer information 44 is matched with the head address of the general-purpose frame buffer 32. Conversely, the display switching unit 21 matches the content of the second frame buffer information 44 with the start address of the high-speed frame buffer 31 when the content of the first frame buffer information 43 matches the start address of the general-purpose frame buffer 32. The first drawing performance information 41 and the second drawing performance information 42 will be described later.

(2) Software part (Frame buffer management part 11)
The frame buffer management unit 11 secures an area as the high-speed frame buffer 31 on the high-speed memory device 18 according to the number of applications using the frame buffer and the number of components included in the application, and general-purpose on the general-purpose memory device 19. An area is secured as the frame buffer 32.

In the present embodiment, as an example, the frame buffer management unit 11 secures the same number of frame buffers as the number of components that use the frame buffer, but is not limited thereto. If there are a plurality of buffers used by each application and component, the necessary number may be secured. Further, the securing of the frame buffer may be performed statically or dynamically.

The frame buffer management unit 11 holds the reserved start address of the high-speed frame buffer 31 as the high-speed frame buffer start address 114, and holds the reserved start address of the general-purpose frame buffer 32 as the general-purpose frame buffer start address 115.

(Application part 13)
The application unit 13 includes a first drawing component 61 and a second drawing component 62 as components, and an execution control unit 63. In the present embodiment, the two drawing components to be executed are the first drawing component 61 and the second drawing component 62. However, the present invention is not limited to this, and three or more drawing components may be used.

The application unit 13 is an application that has a function of displaying a map and a function of displaying a photo as an example. The first drawing component 61 has a function of displaying a map, and the second drawing component 62 has a function of displaying a photograph. The composition management unit 14 superimposes the map image generated by the first drawing component 61 and the photographic image generated by the second drawing component 62 separately from the map image. As a result, the map is displayed on the entire display area of the display 35, and a photograph of a point on the map is displayed in the vicinity of the point on the map. A display in which two images with a photograph are superimposed is made.

The first drawing component 61 includes a first drawing engine unit 71 and a first execution management unit 72.

The first drawing engine unit 71 performs a drawing process using a buffer specified by the first frame buffer information 43 stored in the information storage unit 17.

The first execution management unit 72 is a processing unit that manages the drawing process of the first drawing component 61, gives a drawing command to the first drawing engine unit 71, and stores the first drawing performance information 41 in the information storage unit 17. Store.

The first drawing performance information 41 is information relating to the drawing performance of the first drawing component 61, and includes drawing required time information, drawing interval information, and previous drawing start time. The drawing required time indicates the time from the start of generation processing of image data to be drawn to writing of the generated image data into the frame buffer. The drawing interval indicates a time interval for drawing image data. For example, if the drawing component processes each frame at 15 fps (frame per second), the drawing interval is 1/15 seconds. The drawing interval is determined in advance. The previous drawing start time is recorded for each start of the drawing process.

The second drawing component 62 includes a second drawing engine unit 73 and a second execution management unit 74.

The second drawing engine unit 73 performs a drawing process using a buffer specified by the second frame buffer information 44 stored in the information storage unit 17.

The second execution management unit 74 is a processing unit that manages the drawing process of the second drawing component 62, gives a drawing command to the second drawing engine unit 73, and stores the second drawing performance information 42 in the information storage unit 17. .

The second drawing performance information 42 is information related to the drawing performance of the second drawing component 62, and includes drawing required time information, drawing interval information, and previous drawing start time. The drawing required time and the drawing interval are the same as those described for the first drawing performance information 41.

The execution control unit 63 performs control such as activation, execution, stop, and termination of the first drawing component 61 and the second drawing component 62 based on user operation information received from the input unit 16. Moreover, the execution control part 63 notifies user operation information etc. to the 1st execution management part 72 and the 2nd execution management part 74 as needed.

(Display switching unit 21)
The display switching unit 21 includes a switching determination unit 81 and a switching execution unit 82.

The switching determination unit 81 acquires the first drawing performance information 41 and the second drawing performance information 42 from the information storage unit 17, and uses the first drawing performance information 41 and the second drawing performance information 42 to use the first drawing component 61. The CPU load when each of the second drawing components 62 executes the drawing process is calculated.

The CPU load may be actually measured, but is not actually measured in the present embodiment, and is simply calculated by the following formula.

CPU load = drawing time / drawing interval (Formula 1)
Then, the switching determination unit 81 determines whether it is necessary to switch the frame buffer used by each drawing component based on the calculated CPU load. If it is determined that the buffer switching is necessary, the switching determination unit 81 switches the buffer to the switching execution unit 82. Request execution. Here, the switching determination unit 81 determines that the buffer switching is necessary when the drawing component having a high CPU load does not perform the drawing process using the high-speed frame buffer 31 capable of high-speed drawing. However, if drawing processing is performed using the high-speed frame buffer 31 capable of high-speed drawing, it is determined that buffer switching is unnecessary.

When the switching execution unit 82 receives a switching execution request from the switching determination unit 81, the switching execution unit 82 acquires the start address of the high-speed frame buffer 31 and the start address of the general-purpose frame buffer 32 from the frame buffer management unit 11. Then, the head address of the high-speed frame buffer 31 is written to the one corresponding to the drawing component that requires high-speed drawing out of the first frame buffer information 43 and the second frame buffer information 44 in the information storage unit 17, and the general-purpose frame is written to the other. Write the start address of the buffer 32.

For example, if the switching determination unit 81 determines that buffer switching is necessary and the drawing component requiring high-speed drawing is the first drawing component 61, the start address of the high-speed frame buffer 31 corresponds to the first drawing component 61. The first frame buffer information 43 to be written is written in the information storage unit 17. At this time, the head address of the general-purpose frame buffer 32 is written as the second frame buffer information 44 corresponding to the second drawing component 62.

Further, the switching execution unit 82 notifies the composition management unit 14 of the change of the overlap setting at the time of composition by switching the frame buffer. Here, the overlap setting defines which of the image drawn in the high-speed frame buffer 31 and the image drawn in the general-purpose frame buffer 32 is displayed above.

Here, a case where buffer switching occurs will be described using a specific example.

When the user operates the map and continuously updates the displayed map image, the CPU load of the first drawing component 61 is higher than the CPU load of the second drawing component 62, so the first drawing component 61 uses the high-speed frame buffer 31. At this time, the second drawing component 62 uses the general-purpose frame buffer 32. Here, when the user performs an operation such as enlarging and displaying a specific photo, the operation target of the user changes from a map to a photo. At this time, the CPU load of the second drawing component 62 may be higher than the CPU load of the first drawing component 61. At this time, buffer switching processing is performed. After the switching process, the second drawing component 62 uses the high-speed frame buffer 31, and the first and second drawing components 62 use the general-purpose frame buffer 32.

(Composite management unit 14)
The composition management unit 14 superimposes the image generated from the data stored in the high-speed frame buffer 31 and the image generated from the data stored in the general-purpose frame buffer 32 based on the overlap setting received from the switching execution unit 82. The synthesized image generated by the synthesis is written into the display frame buffer 33.

1.2. Operation Hereinafter, buffer switching processing in the information processing terminal 1 will be described.

FIG. 2 is a flowchart showing the flow of buffer switching processing according to the present embodiment.

In the information processing terminal 1, it is assumed that the application unit 13 has already been started and the first drawing component 61 and the second drawing component 62 are respectively performing drawing processing. In this state, it is assumed that the buffer switching process is performed at regular intervals. However, the present invention is not limited to this, and may be performed at an appropriate time. For example, it may be performed every time there is a user instruction.

First, the switching determination unit 81 acquires the first drawing performance information 41 and the second drawing performance information 42 from the information storage unit 17, and based on the acquired first drawing performance information 41 and the second drawing performance information 42, The CPU loads of the first drawing component 61 and the second drawing component 62 are calculated based on the above formula 1 (S101).

Next, the switching determination unit 81 refers to the CPU load of the first drawing component 61 and the CPU load of the second drawing component 62, and determines whether or not the drawing component with the highest CPU load is drawing in the high-speed frame buffer 31. Determine (S102). Specifically, frame buffer information (first frame buffer information 43 and second frame buffer information 44) corresponding to the drawing component with the highest CPU load (either the first drawing component 61 or the second drawing component 62). Is determined by whether or not the start address of the high-speed frame buffer matches. If they match, the drawing component with the highest CPU load is drawing in the high-speed frame buffer 31, and if they do not match, the drawing component with the highest CPU load is not drawing in the high-speed frame buffer 31. Become.

If the drawing component with the highest CPU load is drawing in the high-speed frame buffer 31 (Yes in S102), the switching determination unit 81 determines that buffer switching is not necessary, and ends the buffer switching process. On the other hand, when it is determined that the drawing component with the highest load is not being drawn in the high-speed frame buffer 31 (No in S102), the switching determination unit 81 determines that buffer switching is necessary, and the switching execution unit 82 performs buffer switching. Request execution.

Upon receiving the buffer switching execution request, the switching execution unit 82 inquires of the first execution management unit 72 and the second execution management unit 74 about the execution state (whether drawing processing is being performed), and the first drawing component 61 and the second drawing. After both drawing processes of the component 62 are completed, the first execution management unit 72 and the second execution management unit 74 are instructed not to execute the drawing process (S103). This is because if an instruction to interrupt the drawing process is given during the drawing process, the image displayed on the display 35 is disturbed. Note that when both the first drawing component 61 and the second drawing component 62 are not in the drawing process, the switching execution unit 82 instructs to not execute the drawing process immediately.

Next, the switching execution unit 82 acquires the start address of the high-speed frame buffer 31 and the start address of the general-purpose frame buffer 32 from the frame buffer management unit 11 (S104).

Next, the switching execution unit 82, in S102, the frame buffer information corresponding to the drawing component (either the first drawing component 61 or the second drawing component 62) determined by the switching determination unit 81 to have a high CPU load (one of the first drawing component 61 and the second drawing component 62). The contents of the first frame buffer information 43 or the second frame buffer information 44) are rewritten with the head address of the high-speed frame buffer 31. Further, the switching execution unit 82 rewrites the contents of the frame buffer information corresponding to the drawing component that has not been determined to have a high CPU load with the head address of the general-purpose frame buffer 32 (S105).

Thus, a high-speed frame buffer (high-speed frame buffer 31) is allocated to the drawing component determined to have a high CPU load, and the high-speed frame buffer 31 is used for the subsequent drawing processing.

Next, the switching execution unit 82 notifies the composition management unit 14 and changes the overlap setting at the time of composition between the high-speed frame buffer 31 and the general-purpose frame buffer 32 (S106). For example, before switching, a map image is stored in the high-speed frame buffer 31, a photographic image is stored in the general-purpose frame buffer 32, and stored in the general-purpose frame buffer 32 on the map image stored in the high-speed frame buffer 31. It is assumed that the photographed images are displayed in a superimposed manner. In this case, after switching, a map image is stored in the general-purpose frame buffer 32 and a photographic image is stored in the high-speed frame buffer 31. When the overlap setting is not changed, the map image stored in the general-purpose frame buffer 32 is displayed on the photographic image stored in the high-speed frame buffer 31, and only the map image is displayed on the display 35 after all. Will end up. In order to avoid this, the overlap setting is changed so that the overlap order of the image stored in the high-speed frame buffer 31 and the image stored in the general-purpose frame buffer 32 is changed.

Finally, the switching execution unit 82 instructs the first execution management unit 72 and the second execution management unit 74 to resume the drawing process (S107). After resuming the drawing process, the drawing component determined to have a high CPU load by the switching determination unit 81 in S102 performs the drawing process using the high-speed frame buffer 31.

According to such a configuration, while an application having a plurality of drawing components is being executed, even if the CPU load applied to the processing of each drawing component is changed by a user operation or the like, a drawing component with a high CPU load is always rendered. Since drawing is performed on the high-speed frame buffer 31 having a short required time, the CPU load can be reduced, the drawing processing time can be shortened, and the frame rate can be improved and the response to the user operation can be improved. it can.

2. Embodiment 2
In the first embodiment, whether or not it is necessary to switch the buffer is determined according to the CPU load. In the second embodiment, in addition to this, when it is determined that the buffer needs to be switched, a plurality of buffer switching provided in advance is performed. Select the optimum procedure and switch the buffer according to the selected buffer switching procedure. The optimum buffer switching procedure is determined by predicting the occurrence of drawing delay, the occurrence of dropped frames, and the CPU load for each switching procedure, and comprehensively judging from the prediction results.

Here, a plurality of buffer switching procedures are used by (1) a procedure for switching buffers without copying the contents of the buffers to each other (hereinafter referred to as a first switching procedure), and (2) a first drawing component 61. Procedures for copying the contents of the buffer to the buffer used by the second drawing component 62 and then switching the buffer (hereinafter referred to as the second switching procedure), (3) Contents of the buffer used by the second drawing component 62 Are copied to the buffer used by the first drawing component 61, and then the buffer is switched (hereinafter referred to as the third switching procedure). Hereinafter, the procedure of proceeding with the drawing process without switching the buffer is referred to as a fourth switching procedure for convenience.

In the first switching procedure, the contents stored in the buffer immediately before the selection of the buffer switching procedure are discarded, so that each of the first drawing component 61 and the second drawing component 62 is newly set in the buffer switching procedure. Drawing processing is performed using a frame buffer different from that used immediately before selection.

2.1. Configuration FIG. 3 is a block diagram showing an example of the configuration of the information processing terminal 1 according to Embodiment 2 of the present invention.

3, the same components as those in FIG. 1 are denoted by the same reference numerals, and redundant description is omitted.

The information processing terminal 1 according to the present embodiment is different from the configuration of the first embodiment in the following points.
(1) A frame buffer generation management unit 94 and a frame buffer state management unit 93 are provided in the frame buffer management unit 11. The frame buffer generation management unit 94 corresponds to the frame buffer management unit 11 of the first embodiment.
(2) A drawing copy control unit 22 is added.
(3) A switching procedure selection unit 83 and a display time calculation unit 84 are added to the display switching unit 21.
(4) Switching procedure information 45 and display information 46 are added to the information recorded in the information storage unit 17.
(5) The display memory device 20 is provided with a first immediately preceding frame buffer 36 and a second immediately preceding frame buffer 37.
(6) The display switching device 12 includes the information storage unit 17, the display switching unit 21, and the drawing copy control unit 22.

Hereinafter, these differences will be mainly described.
(Frame buffer management unit 11)
The frame buffer management unit 11 includes a frame buffer state management unit 93 and a frame buffer generation management unit 94.

The frame buffer state management unit 93 acquires the display information 46 from the display control unit 34 and records it in the information storage unit 17. In the present embodiment, the display control unit 34 updates the refresh time information at each refresh timing, and notifies the frame buffer state management unit 93 of the latest display information 46 including the latest refresh time information at each refresh timing. And

The frame buffer generation management unit 94 secures a memory area as the high-speed frame buffer 31 on the high-speed memory buffer 18 according to the number of applications using the frame buffer and the number of components included in the application. As a general-purpose frame buffer 32, a memory area is secured. Then, the frame buffer generation management unit 94 holds the reserved start address of the high-speed frame buffer 31 as the high-speed frame buffer start address 114, and holds the reserved start address of the general-purpose frame buffer 32 as the general-purpose frame buffer start address 115. Here, in this embodiment, the frame buffer generation management unit 94 secures the same number of frame buffers as the number of components that use the frame buffer. More specifically, two frame buffers, ie, a high-speed frame buffer 31 in the high-speed memory device 18 and a general-purpose frame buffer 32 in the general-purpose memory device 19 are secured. However, the provision of two frame buffers is determined for the sake of brevity and is not limited to this. When there are a plurality of buffers used by each application and component, the necessary number or a part of the necessary number may be secured without being limited to two. Further, the securing of the frame buffer may be performed statically or dynamically. In addition, as long as the memory area of the high-speed frame buffer 31 permits, the drawing processing capability is improved by securing the frame buffer on the high-speed frame buffer 31.

The frame buffer generation management unit 94 further includes a first conversion coefficient for converting the time required for drawing processing using the high-speed frame buffer 31 to the time required when the same drawing processing is performed using the general-purpose frame buffer 32, And the 2nd conversion coefficient which converts the required time of the drawing process using the general-purpose frame buffer 32 into the required time when the same drawing process is performed using the high-speed frame buffer 31 is held. For example, when the same drawing process is performed using the high-speed frame buffer 31 and the general-purpose frame buffer 32, it takes 0.1 seconds when the high-speed frame buffer 31 is used, and 0.2 seconds when the general-purpose frame buffer 32 is used. If so, the first transform coefficient is 2, and the second transform coefficient is 0.5.
(Drawing copy control unit 22)
In accordance with the copy request, the drawing copy control unit 22 copies the content recorded in one of the high-speed frame buffer 31 and the general-purpose frame buffer 32 to the other, and also copies the content recorded in both to each other. Replace.
(Display switching unit 21)
The display switching unit 21 includes a switching procedure selection unit 83 and a display time calculation unit 84 in addition to the switching determination unit 81 and the switching execution unit 82.
(Display time calculation unit 84)
The display time calculation unit 84 receives a display time calculation request specifying any one of the first to fourth switching procedures from the switching procedure selection unit 83. Then, the display time calculation unit 84 calculates the start time and the end time of each drawing process periodically performed by each of the first drawing component 61 and the second drawing component 62. Then, the refresh timing at which the image generated and written by each drawing process is displayed is calculated. Based on the information calculated by the display time calculation unit 84, the switching procedure selection unit 83 comprehensively evaluates frame image display delay, frame dropping, and CPU load increase by each switching procedure, and the switching procedure is selected. The

FIG. 4 is a flowchart showing a display time calculation process performed by the display time calculation unit 84.

FIG. 5 is a timing chart showing a drawing process when the second switching procedure is performed. In addition, a figure schematically representing the screen image to be drawn is added to the timing chart.

Hereinafter, for convenience of explanation, FIG. 5 will be described first. Thereafter, the flowchart of FIG. 4 will be described with reference to FIG. 5 as an example where the first switching procedure is designated.

The horizontal axis t in FIG. 5 indicates time.

The vertical axis of FIG. 5 is divided into high-speed FB (frame buffer), general-purpose FB, and display FB columns. The high-speed FB column indicates that the drawing process is performed using the high-speed frame buffer 31. The FB column indicates that the drawing process is performed using the general-purpose frame buffer 32, and the display FB column indicates that the drawing process is performed using the display frame buffer 33.

In FIG. 5, TRa (a is an integer, and a = -1, 0, 1 to 5 in the figure) indicates a refresh timing. The interval between the refresh timings is a fixed time TI. The TI is refresh interval information included in the display information 46, and is determined by performance, specifications, etc. relating to display on the display.

The drawing b bar (b = 1, 2) represents that the b-th drawing component performs the drawing process in the processing period indicated by the width of the bar in the time axis direction.

For example, the drawing 1 bar 201 represents that the first drawing component 61 performs the drawing process in the processing period (TD1) indicated by the width of the bar in the time axis direction. The drawing 1 bar 201 is described in the high-speed FB column, and this drawing process is performed using the high-speed frame buffer 31. The process shown in the drawing 1 bar 201 starts at time T10 and ends at time T11.
The drawing 1 bars 202 to 205 are the same as the drawing 1 bar 201. However, the drawing 1 bars 203 to 205 are described in the general-purpose FB column, and this drawing processing is performed using the general-purpose frame buffer 32. The processing period (TD4) of the drawing 1 bars 203 to 205 is longer than that of the drawing 1 bars 201 to 202 using the high-speed frame buffer 31 (TD1 <TD4).

The drawing 2 bar 211 indicates that the second drawing component 62 performs the drawing process in a period (TD2) indicated by the width of the bar in the time axis direction. The drawing 2 bar 211 is described in the general-purpose FB column, and this drawing processing is performed using the general-purpose frame buffer 32. The process indicated by the drawing 2 bar 211 starts at T11 when the drawing process indicated by the drawing 1 bar 201 ends, and ends at time T12. The drawing 2 bars 212 to 214 are the same as the drawing 2 bar 211. However, the drawing 2 bars 212 to 214 are described in the high-speed FB column, and these drawing processes are performed using the high-speed frame buffer 31, and the processing period (TD3) is longer than that of the drawing 2 bar 211. Shorter (TD2 <TD3).

T13 to T20 also indicate the start time and end time of the drawing process, respectively, similarly to T10 to T12.

The composite bar 221 indicates that a composite image is generated by the composite management unit 14 and displayed on the display 35 by the display control unit 34 in a period indicated by the width of the bar in the time axis direction. The drawing process indicated by the synthesis bar 221 starts at the refresh timing TR0. The composite bar 221 is described in the display FB column, and indicates that this drawing process is performed using the display frame buffer 33. The synthesis bars 222 to 225 are the same as the synthesis bar 221.

The memory copy bar 231 indicates that the contents of the high-speed frame buffer 31 are being copied to the second frame buffer 32 by the drawing copy control unit 22 during the period indicated by the width of the bar in the time axis direction. TDC indicates the time required for copying.

The rectangle (image 251) shown in the balloon from the drawing 1 bar 201 schematically represents the image data that the first drawing component 61 writes to the frame buffer and the image image displayed on the display 35 based on the image data. Show. A numerical value “0” in the image 251 indicates a number (frame number) given to the image written by the first drawing component 61. Note that the frame numbers are merely used for convenience to indicate the relative order of the images, and the numbers themselves do not have any special intention.

Similarly, from the drawing 2 bar 211, the hatched rectangle (image 261) shown in the balloon is the image data that the second drawing component 62 writes to the frame buffer and the image displayed on the display 35 based on the image data. The image is shown schematically. The numerical value “1” in the image 261 indicates the frame number assigned to the image written by the second drawing component 62.

Also, the rectangle (image 271) shown in the balloon area from the synthesis bar 221 schematically shows the image that the synthesis management unit 14 writes to the display frame buffer 33. This image 271 is an image in which the image 282 is combined with the image 251.

The images 252 to 255 are the same as the image 251. The images 262 to 264 are the same as the image 261. The images 272 to 275 are the same as the image 271.

Next, a description will be given according to the flowchart of FIG. 4 with reference to FIG.

In the display time calculation process according to FIG. 4, as described above, the start time and end time (T11 to T20) of each of the drawing processes periodically performed by each of the first drawing component 61 and the second drawing component 62 are calculated. . Also, it is calculated at which refresh timing (TR0 to TR4, etc.) the images generated and written by each drawing process (images 251 to 264, etc., images 261 to 255, etc.) are displayed.

Specifically, first, the switching procedure selection unit 83 transmits a display time calculation request including the provisional switching start time and specifying the calculation target procedure to the display time calculation unit 84. The calculation target procedure indicates one of the first to fourth switching procedures. Here, it is assumed that the calculation target procedure is the second switching procedure. The switching start provisional time is determined by the switching procedure selection unit 83 as follows. That is, when the switching procedure selection unit 83 tries to transmit the display time calculation request, if neither the first drawing component 61 nor the second drawing component 62 is performing the drawing process, the switching procedure selection unit 83 sets the current time to the temporary switching start time. And If either the first drawing component 61 or the second drawing component 62 is in the drawing process, the temporary start time for switching is set immediately after the end of the drawing process. In the example of FIG. 5, the switching procedure selection unit 83 includes TC (T13) immediately after the end of the drawing process as the switching start temporary time in the display time calculation request.

The refresh timing TRa (a is an integer) is assigned a value with a refresh timing immediately before TC as TR0. The frame number is assigned in order with the frame number of the image drawn immediately before TC being set to 1.

The display time calculation unit 84 receives the display time calculation request from the switching procedure selection unit 83 and starts processing. The display time calculation unit 84 stores the temporary switching start time included in the display time calculation request in the variable t (S401).

Next, the display time calculation unit 84 acquires the first drawing information 41 and the second drawing information 42 from the information storage unit 17. Then, for the first drawing component 61, the drawing start time immediately before t is calculated (S402). In the example of FIG. 5, the drawing start time is the start time T12 of the drawing 1 bar 202 indicated by the previous drawing start time information included in the first drawing information 41. The display time calculation unit 84 prepares integer type variables m and n. m indicates the serial number of the image drawn by the second drawing component, and n indicates the serial number of the image drawn by the first drawing component. The frame number (n) of the image related to the start time calculated in S402 is set to 1.

Similarly, for the second drawing component 62, the drawing start time immediately before t is calculated (S403). In the case of the example in FIG. 5, the drawing start time is the start time T11 of the drawing 2 bar 211 indicated by the previous drawing start time information included in the second drawing information 42. The frame number (m) of the image related to the start time calculated in S403 is set to 1.

Next, the display time calculation unit 84 determines whether or not the calculation target procedure is the second switching procedure (S403). If it is the second switching procedure (S403: YES), it is stored in the high-speed frame buffer 31. Completion time (T14) when the content is copied to the general-purpose frame buffer 32 is calculated and stored in t (S404). It is assumed that the time TDC required to copy the contents stored in the high-speed frame buffer 31 to the general-purpose frame buffer 32 is known.

Next, the display time calculation unit 84 determines whether or not the calculation target procedure is the third switching procedure (S405). If the calculation procedure is the third switching procedure (S405: YES), the display time calculation unit 84 is stored in the general-purpose frame buffer 32. The completion time when the content is copied to the high-speed frame buffer 31 is calculated and stored in t (S406). It is assumed that the time required to copy the contents stored in the general-purpose frame buffer 32 to the high-speed frame buffer 31 is known.

Next, the display time calculation unit 84 sets m and n to 2 (S407).

Next, the display time calculation unit 84 determines which drawing component is to perform the drawing process at the time closest to the time t after the time t (S406).

If it is determined in S408 that the component is the first drawing component 61, the process proceeds to S411, and if it is determined that the component is the second drawing component 62, the process proceeds to S409. In the case of FIG. 5, the drawing component that starts the drawing process at the time closest to time t (= TC) is the second drawing component that starts the process at the start time T14 closest to time t.

If it is determined in S408 that it is the second drawing component 62 (S408: second drawing component), the display time calculation unit 84 calculates the drawing processing end time of the drawing processing that starts at the time closest to time t, It is overwritten and stored in t (S409).

In the case of FIG. 5, the drawing process end time is T15 which is the last of the drawing 2 bar 212, and T15 is overwritten and stored in t.

Note that the time required for the processing indicated by each drawing bar after TC is only an estimate at the time of TC. In addition, the time required for the drawing process may not be the same for all the drawing processes, but here, the time required for the drawing process performed immediately before t is the time required for the drawing process to be performed thereafter. I reckon. However, if the frame buffer used for the most recently performed drawing process is different from the frame buffer used for the subsequent rendering process, the required time measured for the most recently performed rendering process is performed later. It cannot be regarded as the time required for the power drawing process. Therefore, the required time measured for the most recently performed drawing process is multiplied by the first or second conversion coefficient, and is regarded as the time required for the drawing process to be performed thereafter. The drawing processing time may be a predetermined time, an average drawing processing time, or the like.

Next, the display time calculation unit 84 acquires the display information 46 from the information storage unit 17, and calculates the latest refresh timing after time t using the refresh time information included in the display information 46. The display time calculation unit 84 holds this refresh timing as the m-th screen display time of the second drawing component 62 (S410). In the example of FIG. 5, T15 is set to t in S409, and the latest refresh timing TRa (a = 2) after T15 is the m (= 2) th refresh timing of the second drawing component 62. . At this time, a is held as the screen display time.

Next, the display time calculation unit 84 calculates and holds the drawing start time of the mth drawing frame of the second drawing component 62 (S411). In the case of FIG. 5, the m (= 2) -th drawing start time of the second drawing component 62 is T14.

Through the processes of S409 to S411, the display time calculation unit 84 displays the drawing start time, the drawing end time, and the m (= 2) -th image of the m (= 2) -th image of the second drawing component 62. The refresh timing is calculated.

Next, the display time calculation unit 84 adds 1 to m (S412), and transitions to S417.

The display time calculation unit 84 determines whether or not the processing from S409 to S412 or S414 to S416 is performed again based on the time t (S417). The determination is based on whether t has reached a predetermined upper limit. The upper limit value may be reset based on the time required for this process.

If it is determined in S417 that the process is to be performed again (S417 is NO), the process proceeds to S408, and if it is not determined that the process is to be performed again (S417 is YES), the process is terminated. In the present embodiment, it is assumed that the calculation process does not end for the time until m and n become 4, and the upper limit value is set so that S417 is NO.

In the example of FIG. 5, when t first shifted from S417 to S408, t was T15. Therefore, in S408, the drawing component that performs the drawing process immediately after time t is determined to be the first drawing component 61. S413 to S416 executed at this time are the same as S409 to S412 described above for the second drawing component 61 except that the second drawing component 62 has been replaced with the first drawing component 61 and that the variable m has been replaced with n. It is the same. Therefore, further explanation of S413 to S416 is omitted. Through the processes of S413 to S415 described above, the display time calculation unit 84 displays the drawing start time, the drawing end time, and the m (= 2) -th image of the m (= 2) -th image of the first drawing component 61. The refresh timing is calculated.

As a result of the above processing, for each of the second drawing component 62 and the first drawing component 61, the drawing start time, the drawing end time, and the refresh timing at which the image is displayed for each of m = 1 to 4 are calculated. .

FIG. 6 is a timing chart showing a drawing process for the fourth switching procedure.

Referring to the figure, symbols, etc. in FIG. 6 is the same as in FIG.

The difference between the fourth switching procedure in FIG. 6 and the second switching procedure in FIG. 4 is largely that the memory contents shown as the memory copy bar 231 in FIG. 4 are not copied, and the first drawing component 61 in TC. And the memory buffer used by the second drawing component 62 is not switched.

Also for the fourth switching procedure, by using the flowchart of FIG. 4, for each of the drawing processes of the drawing 1 bars 201 to 202, 311 to 313 and the drawing 2

bars

211 and 321 to 323, images of m = 1 to 4 respectively. The drawing start time, drawing end time, and refresh timing at which the image is displayed are calculated.

FIG. 7 is a timing chart showing a drawing process for the first switching procedure.

7 The method of referring to the figures, symbols, etc. in FIG. 7 is the same as in FIG.

The difference between the first switching procedure in FIG. 7 and the second switching procedure in FIG. 4 is that the memory contents shown as the memory copy bar 231 in FIG. 4 are not copied.

Also for the first switching procedure, by using the flowchart of FIG. 4, for each of the drawing processes of the drawing 1 bars 201 to 202 and 361 to 363 and the drawing 2

bars

211 and 351 to 353, images of m = 1 to 4 respectively. The drawing start time, drawing end time, and refresh timing at which the image is displayed are calculated.

FIG. 8 is a timing chart showing a drawing process for the third switching procedure.

Referring to the figure, symbols, etc. in FIG. 8 is the same as in FIG.

The difference between the third switching procedure in FIG. 8 and the second switching procedure in FIG. 4 is that the copy source and the copy destination are reversed in the copy of the memory contents shown as the memory copy bar 231 in FIG. It is. That is, the contents stored in the general-purpose frame buffer 32 are copied to the high-speed frame buffer 31 (represented as a memory copy bar 231).

Also for the third switching procedure, by using the flowchart of FIG. 8, for each of the drawing processes of the drawing 1 bars 201 to 202, 381 to 383, and the drawing 2

bars

211 and 391 to 393, images of m = 1 to 4 respectively. The drawing start time, drawing end time, and refresh timing at which the image is displayed are calculated.

FIG. 9 is a table summarizing the calculation results by the display time calculation process for the first to fourth switching procedures.

FIG. 9A shows at which refresh timing (“a” of TRa) the frame number (m, n), the first drawing component 61, and the second drawing component are displayed in the fourth switching procedure. Indicates. The frame number in FIG. 9A indicates the values of m and n.

For example, the value in the column 511 in FIG. That is, the image 223 of frame number 1 of the first drawing component 61 is displayed at the refresh timing TR1. The value in the column 512 in FIG. That is, the image 222 of the frame number 1 of the second drawing component 62 is displayed at the refresh timing TR0. Also, the value in the column 513 in FIG. That is, the image 225 of the frame number 2 of the first drawing component 61 is displayed at the refresh timing TR2. The value in the column 514 in FIG. That is, the image 224 of frame number 2 of the second drawing component 62 is displayed at the refresh timing TR2. The value in the column 515 in FIG. That is, the image 227 of frame number 3 of the first drawing component 61 is displayed at the refresh timing TR3. The value in the column 516 in FIG. That is, the image 226 of frame number 3 of the second drawing component 62 is displayed at the refresh timing TR3.

FIGS. 9B, 9C, and 9D show the frame number (m, n), the first drawing component 61, and the second in the first to third switching procedures, respectively. For each drawing component, the refresh timing (TRa “a”) is displayed.

9B, 9C, and 9D are provided with delay columns (column 521 and column 522) that are not described in FIG. 9A.

This is a description of the delay that occurs when the first switching procedure according to FIG. 9B is employed compared to the case where the fourth switching procedure according to FIG. 9A is employed. The smaller the delay, the better.

In the column 521 of FIG. 9B, −1 is described as the delay.

This indicates that with respect to the first drawing component 61, when the first switching procedure is adopted, the delay is reduced by 1 compared to the case where the fourth switching procedure is adopted. Specifically, the refresh timing at which the fourth frame is displayed is 5 (TR5) in the fourth switching procedure, while 4 (TR4) is displayed in the first switching procedure.

Further, the value -3 is described in the column 522 of FIG.

This is because, for the second rendering component 62, the refresh timing at which frames with

frame numbers

2, 3, and 4 are displayed is 2 (TR2), 3 (TR3), and 4 (TR4) in the fourth switching procedure. On the other hand, in the first switching procedure, 1 (TR1), 2 (TR2), and 3 (TR3) are displayed, and the refresh timing displayed is incremented by 1, so the total value is -3. is there.

FIGS. 9E to 9G are tables showing the scores of the first to third switching procedures.

FIG. 9 (e) is a table showing the score of the first switching procedure, and corresponds to FIG. 9 (b).

The delay meter in FIG. 9 (e) is the sum of the delays in FIG. 9 (b). Specifically, it is the sum of the values in the

columns

521 and 522.

The frame dropping in FIG. 9 (e) occurs when image data is recorded in the buffer and then image data is recorded again in the buffer before the refresh timing comes.

As an example, in the drawing 1 bar 202 of FIG. 7 showing the first switching procedure corresponding to FIGS. 9E and 9B, the image 252 is described in the high-speed frame buffer, but before the refresh timing comes. In addition, the image 262 is overwritten in the high-speed frame buffer by the drawing process related to the drawing 2 bar 361. Therefore, the image 252 is dropped.

Whether or not frames are dropped is determined by whether or not drawing processing for overwriting another image data is started before the refresh timing comes after the image data is written to the high-speed frame buffer. Can do. This determination result is described in the frame dropout column in FIG.

The load in FIG. 9 (e) indicates the CPU load.

Describe 0.1 as the load value when copying the contents from one of the high-speed frame buffer and general-purpose frame buffer to the other. A load is generated in the second switching procedure and the third switching procedure.

The score in FIG. 9 (e) is the sum of the values in the delay meter column, the frame drop column, and the load column.

FIG. 9 (f) is a table showing the score of the second switching procedure, and corresponds to FIG. 9 (c).

FIG. 9 (g) is a table showing the score of the third switching procedure, and corresponds to FIG. 9 (d).

9F and 9G are the same as those in FIG. 9E, and the description thereof is omitted.

(Switching procedure selection unit 83)
The switching procedure selection unit 83 calculates a score representing the buffer switching cost for each of the first switching procedure to the fourth switching procedure.

The switching procedure selection unit 83 acquires the calculation results shown in FIGS. 9A to 9D from the display time calculation unit 84. Then, based on the display time calculation result acquired from the display time calculation unit 84, a score representing the buffer switching cost is calculated for each of the first switching procedure to the fourth switching procedure. Since the score has already been described with reference to FIGS. 9E to 9G, description thereof will be omitted.

The switching procedure selection unit 83 compares the calculated scores, and selects a switching procedure with a low score as the optimum switching procedure. Then, the switching procedure information 45 indicating the selected switching procedure is stored in the information storage unit 17.

FIG. 10 is a flowchart of the switching procedure selection process performed by the switching procedure selection unit 83.

The switching procedure selection unit 83 receives the switching procedure selection start request from the switching determination unit 81 and starts the switching procedure selection process.

The switching procedure selection unit 83 first prepares an integer type variable i and sets 0 as an initial value (S301).

And the switching procedure selection part 83 calculates the above-mentioned switching start temporary time. Here, as described above, the switching procedure selection unit 83, when trying to transmit a calculation request, sets the current time if neither the first drawing component 61 nor the second drawing component 62 is in the drawing process. This is the provisional switching start time. If either the first drawing component 61 or the second drawing component 62 is in the drawing process, the temporary start time for switching is set immediately after the end of the drawing process. If i is not 0, for the drawing component whose switching start provisional time is immediately after the end of the drawing process, the switching start provisional time immediately after i drawing process is performed (S302).

For example, in FIG. 5, when i is 0, the switching start temporary time is immediately after the end of the drawing 1 bar 202, but when i is 1, the drawing 1 bar 203 that is the next drawing 1 bar of the drawing 1 bar 202. Immediately after the end of, the temporary switching start time is set. When i is 1, the switching start provisional time may be immediately after the end of the drawing 2 bar 212 which is the next drawing 2 bar of the drawing 1 bar 202.

Next, the switching procedure selection unit 83 makes a display time calculation request for the fourth switching procedure that does not perform buffer switching to the display time calculation unit 84, and acquires a calculation result (hereinafter referred to as a fourth calculation result) ( S303). The process of S303 is executed according to the flowchart of FIG. This calculation result is shown in FIG.

Next, the switching procedure selection unit 83 makes a display time calculation request for the first switching procedure to the display time calculation unit 84, and acquires a calculation result (hereinafter referred to as a first calculation result) (S304). The process of S304 is executed according to the flowchart of FIG. This calculation result is shown in FIG.

Next, the switching procedure selection unit 83 makes a display time calculation request for the second switching procedure to the display time calculation unit 84, and acquires a calculation result (hereinafter referred to as a second calculation result) (S305). The process of S305 is executed according to the flowchart of FIG. This calculation result is shown in FIG.

Next, the switching procedure selection unit 83 makes a display time calculation request for the third switching procedure to the display time calculation unit 84, and acquires a calculation result (hereinafter referred to as a third calculation result) (S306). The process of S306 is executed according to the flowchart of FIG. This calculation result is shown in FIG.

Next, the switching procedure selection unit 83 retains information indicating the scores calculated for the first to third switching units (S307).

Next, it is checked whether or not the integer type i declared in S301 has reached the upper limit. If the upper limit has not been reached (NO in S308), 1 is added to i, and the processing from S302 is performed again (S308). . If the upper limit has been reached (YES in S308), select the procedure that holds the score with the best average score (i.e., the score value is low) calculated i times when i is changed, and the switching start time The method and cost are stored in the information storage unit 17 as the switching procedure information 45 (S319).

Note that the upper limit of the value of i may be set with a fixed threshold for the number of temporary settings. Also, when the processing time of the switching procedure selection process exceeds a certain value, i may be set as the upper limit, and the process may proceed to S309. The upper limit of i may be 1. In S309, the switching procedure with the highest score may be selected without selecting the one with the best average score.
(Switching determination unit 81)
The switching determination unit 81 compares the switching cost of the procedure selected by the switching procedure selection unit 83 with the stored threshold value. When the switching cost is equal to or higher than the threshold, the switching determination unit 81 determines not to perform switching and ends the process. On the other hand, when the switching cost is less than the threshold value, the switching determination unit 81 determines to perform switching, and requests the switching execution unit 82 to perform switching. In addition, it is good also as performing buffer switching by the switching procedure which the switching procedure selection part 83 selected, without comparing a threshold value and cost.

2.2. Operation Hereinafter, the display switching operation in the second embodiment will be described.

FIG. 11 is a flowchart showing an example of the buffer switching operation in the second embodiment.

It is assumed that the application 13 of the information processing terminal 1 is activated and each of the first drawing component 61 and the second drawing component 62 is performing drawing processing.

Further, the switching operation shown in FIG. 11 is performed at regular intervals. However, the present invention is not limited to this, and notification may be received and processing may be started every time a user operation is performed.

First, the switching determination unit 81 calculates the CPU load of each of the first drawing component 61 and the second drawing component 62 by the same processing as S101 (S201).

Next, the switching determination unit 81 refers to the CPU load of the first drawing component 61 and the CPU load of the second drawing component 62 by the same processing as S102, and the drawing component with the highest load is stored in the high-speed frame buffer 31. It is determined whether or not drawing is performed (S202).

When it is determined that the drawing component with the highest load is drawing in the high-speed frame buffer 31 (YES in S202), the switching determination unit 81 determines that switching is not necessary, and ends the processing.

On the other hand, when the drawing component with the highest load is not drawn in the high-speed frame buffer 31 (NO in S202), the switching determination unit 81 instructs the switching procedure selection unit 83 to select the switching procedure. The switching procedure selection unit 83 performs a switching procedure selection process (S203).

The switching procedure selection unit 83 selects an optimal procedure from the first switching procedure to the fourth switching procedure, and stores the selected procedure in the information storage unit 17 as the switching procedure information 45 (S204).

S204 is processed according to the flowchart described in FIG.

The switching determination unit 81 acquires the switching procedure information 45 from the information storage unit 17 (S205).

Then, the switching determination unit 81 compares the switching cost of the procedure selected by the switching procedure selection unit 83 with the held threshold value. When the switching cost is equal to or higher than the threshold value, the switching determination unit 81 determines not to perform switching (NO in S206), and ends the process. On the other hand, when the switching cost is less than the threshold, the switching determination unit 81 determines to perform switching (YES in S206) and requests the switching execution unit 82 to perform switching.

Next, the switching execution unit 82 reads the execution state of the drawing processing of the first execution management unit 72 and the second execution management unit 74, and after the drawing processing of each drawing component (131, 132) is completed, the first execution is performed. The management unit 72 and the second execution management unit 74 are instructed to stop the drawing process by each drawing component (131, 132) (S207). Note that when all the drawing components (131, 132) are not in the drawing process, the switching execution unit 82 commands an interruption immediately.

Next, the switching execution unit 82 instructs the drawing copy control unit 22 to copy between the frame buffers according to the acquired switching procedure (S208). Specifically, when the switching procedure indicated by the acquired switching procedure information 45 is the second switching procedure, the second rendering component 62 uses the contents of the buffer used by the first rendering component 61. To copy to the current buffer.

When the switching procedure indicated by the acquired switching procedure information 45 is the third switching procedure, the contents of the buffer used by the second drawing component 62 are copied to the buffer used by the first drawing component 61. Instruct them to do so.

Next, the switching execution unit 82 acquires the addresses of the high-speed frame buffer 31 and the general-purpose frame buffer 32 (the high-speed frame buffer start address 91 and the general-purpose frame buffer start address 92) from the frame buffer generation management unit 94. Then, the switching execution unit 82 stores the high-speed frame buffer in the frame buffer information storage unit (124 or 125) corresponding to the drawing component (131 or 132) determined to have a high drawing load by the switching determination unit 81 in step S202. 31 addresses are stored.
Further, the switching execution unit 82 stores the address of the general-purpose frame buffer 32 in the frame buffer information storage unit (124 or 125) corresponding to the drawing component (131 or 132) determined to have a low drawing load (S209). ). Thus, the drawing component determined to have a high drawing load is allocated and set by the high-speed frame buffer (high-speed frame buffer 31), and the high-speed frame buffer is used for the next drawing.

Next, the switching execution unit 82 notifies the composition management unit 14 and changes the overlap setting at the time of composition between the high-speed frame buffer 31 and the general-purpose frame buffer 32 (S210).

Next, the switching execution unit 82 locks the display screen if necessary according to the switching procedure (S211).

Specifically, the switching execution unit 82 instructs the composition management unit 14 to lock the screen, and the composition management unit 14 stops the frame buffer composition processing that may cause a display failure.

Here, the display failure means that the drawing component (131, 132) does not complete the drawing process and displays it on the display 35 in a state where the screen to be displayed is not completed.

Next, the switching execution unit 82 instructs the first execution management unit 72 and the second execution management unit 74 to resume the drawing process that was instructed to be stopped in S207 (S213).

Finally, when the screen is locked in S212, the switching execution unit 82 releases the screen lock at an appropriate timing according to the information stored in the information storage unit 17 (S214). Specifically, the switching execution unit 82 instructs the composition management unit 14 to release the screen lock, and the composition management unit 14 resumes the composition processing of the high-speed frame buffer 31 and the general-purpose frame buffer 32.

As described above, in the information processing terminal 1, after resuming the suspended drawing process, the drawing component determined to have a high drawing load by the switching determination unit 81 in step S202 is drawn using the high-speed frame buffer. Processing will be performed. In addition, display failure and flickering associated with the switching process can be suppressed.
3. Although the present invention has been described based on the above embodiment, the present invention is not limited to the above embodiment, and various modifications can be made without departing from the gist of the present invention. Of course, it can be added.
(1) In the first embodiment, the CPU load is set as the required drawing time / drawing interval, but is not limited thereto. For example, the CPU load may use an average value of a plurality of CPU loads calculated up to the present after the switching determination unit 81 has made the switching determination most recently.
(2) In the above-described embodiment, the information processing terminal 1 is a portable information terminal. However, the information processing terminal 1 is not limited to this and may be a stationary information terminal, a mobile phone, an AV device, or the like. It may be.

In addition, the application executed by the information processing terminal 1 is to draw a map and a photo, but is not limited to this, and is a combination of a map, a movie, a photo, CG (Computer Graphics), document drawing, and the like. May be.

In the above-described embodiment, an example in which two drawing components are included in one application has been described. However, the present invention is not limited to this, and the present invention can be applied to a case where a plurality of drawing processes are performed in parallel. For example, a case where two applications of a map display application and a photo display application are executed in parallel is considered.

(3) Although only two components are used in the first embodiment, three or more components may be used. An X window system (registered trademark) is incorporated in the software section of the information processing terminal 1 (not shown), and the general-purpose frame buffer 32 may perform drawing via the X window system. In this case, if the high-speed frame buffer 31 is drawn without going through the X window system, the drawing process using the high-speed frame buffer 31 is faster than the case where the general-purpose frame buffer 32 is used. Become. Since only a single component designated by the switching determination unit 81, which will be described later, can write data to the high-speed frame buffer 31, the designated component performs drawing processing faster than other components. Can be executed.

On the other hand, with respect to the general-purpose frame buffer 32, two or more components can request to write data at the same time. The X window system arbitrates these write requests, and then sequentially sends the data requested to be written by each component. Write to the general-purpose frame buffer 32. Therefore, the time difference between the time required for the drawing process using the general-purpose frame buffer 32 and the time required for the drawing process using the high-speed frame buffer 31 is larger than that when the X window system is not used.

(4) Specifically, each of the above devices is a computer system including a microprocessor, a ROM, a RAM, a hard disk unit, a display unit, a keyboard, a mouse, and the like. A computer program is stored in the RAM or the hard disk unit. Each device achieves its function by the microprocessor operating according to the computer program. Here, the computer program is configured by combining a plurality of instruction codes indicating instructions for the computer in order to achieve a predetermined function.

Note that each device is not limited to a computer system including all of a microprocessor, ROM, RAM, hard disk unit, display unit, keyboard, mouse, and the like, but may be a computer system including a part of them.

(5) A part or all of the constituent elements constituting each of the above devices is configured by a circuit that realizes the function of the constituent element, or a program that realizes the function of the constituent element and a processor that executes the program Alternatively, it may be configured from one system LSI (Large Scale Integration). The system LSI is a super multifunctional LSI manufactured by integrating a plurality of components on one chip, and specifically, a computer system including a microprocessor, a ROM, a RAM, and the like. . A computer program is stored in the RAM. The system LSI achieves its functions by the microprocessor operating according to the computer program. These may be individually made into one chip, or may be made into one chip so as to include a part or all of them.

Although the system LSI is used here, it may be called IC, system LSI, super LSI, or ultra LSI depending on the degree of integration.

Further, the method of circuit integration is not limited to LSI, and may be realized by a dedicated circuit or a general-purpose processor. An FPGA (Field Programmable Gate Array) that can be programmed after manufacturing the LSI, or a reconfigurable processor that can reconfigure the connection and setting of circuit cells inside the LSI may be used.

Furthermore, if integrated circuit technology that replaces LSI emerges as a result of advances in semiconductor technology or other derived technology, it is naturally also possible to integrate functional blocks using this technology. Biotechnology can be applied.

(6) A part or all of the constituent elements constituting each of the above devices may be configured by an IC card or a single module that can be attached to and detached from each device. The IC card or the module is a computer system including a microprocessor, a ROM, a RAM, and the like. The IC card or the module may include the super multifunctional LSI described above. The IC card or the module achieves its function by the microprocessor operating according to the computer program. This IC card or this module may have tamper resistance.

(7) The present invention may be the method described above. Further, the present invention may be a computer program that realizes these methods by a computer, or may be a digital signal composed of the computer program.

The present invention also provides a computer-readable recording medium such as a flexible disk, hard disk, CD-ROM, MO, DVD, DVD-ROM, DVD-RAM, BD (Blu-ray Disc). ), Recorded in a semiconductor memory or the like. Further, the present invention may be the computer program or the digital signal recorded on these recording media.

In the present invention, the computer program or the digital signal may be transmitted via an electric communication line, a wireless or wired communication line, a network represented by the Internet, a data broadcast, or the like.

In addition, the program or the digital signal is recorded on the recording medium and transferred, or the program or the digital signal is transferred via the network or the like, and is executed by another independent computer system. It is good.

(8) The above embodiment and the above modification examples may be combined.

The display switching device according to the present invention is suitable for an information processing terminal, an AV device, a communication terminal, and the like having a function of displaying a plurality of windows in an overlapping manner.

DESCRIPTION OF SYMBOLS 1 Information processing terminal 11 Frame buffer management part 12 Display switching device 13 Application part 14 Composition management part 15 Display part 16 Input part 17 Information storage part 18 High-speed memory device 19 General-purpose memory device 20 Display memory device 21 Display switching part 22 Drawing copy control Unit 31 high-speed frame buffer 32 general-purpose frame buffer 33 display frame buffer 61 first drawing component 62 second drawing component 63 execution control unit 81 switching determination unit 82 switching execution unit 83 switching procedure selection unit 84 display time calculation unit

Claims

A display switching device for switching a buffer assigned to each of a plurality of drawing components for a high-speed buffer and a general-purpose buffer for drawing an image,
A switching determination unit that repeatedly calculates a drawing processing load for each of the plurality of drawing components;
Each time the drawing processing load is calculated, it is determined whether or not the high-speed buffer is assigned to the highest drawing processing load calculated among the plurality of drawing components. A display switching device comprising: a drawing component having the highest drawing processing load calculated; and a switching execution unit that switches a buffer assigned to the drawing component to which the high-speed buffer is assigned.
The drawing processing load is a time during which each drawing component performs drawing processing per unit time,
2. The switching execution unit selects the one having the longest drawing processing time per unit time as the one having the highest drawing processing load among the plurality of drawing components. Display switching device.
The switching execution unit
A first switching procedure for switching buffers without copying the contents recorded in the high-speed buffer and the general-purpose buffer;
A second switching procedure for switching the buffer after copying the content stored in the high-speed buffer to the general-purpose buffer;
The display switching device according to claim 1, wherein after the content stored in the general-purpose buffer is copied to the high-speed buffer, one of the third switching procedures for switching the buffer is selected.
When the switching execution unit selects the one switching procedure, the switching execution unit estimates a buffer switching cost for each of the switching procedures, compared to a case where the drawing process is continued without switching the buffer after switching the buffer. The display switching device according to claim 3, wherein a procedure having the minimum buffer switching cost is selected.
The display switching device according to claim 4, wherein the buffer switching cost is determined based on at least one of a frame drop number, a display delay number, and a CPU load value.
The display switching device according to claim 4, wherein the buffer switching cost is determined based on a value obtained by adding two or more of the number of dropped frames, the number of display delays, and the CPU load value.
5. The switching execution unit, when displaying a frame image on a screen, if it is determined that there is a process failure, locks the screen display without changing the period during which there is a process failure. Display switching device.
A display switching method used for a display switching device that switches a buffer assigned to each of a plurality of drawing components for a high-speed buffer and a general-purpose buffer for drawing an image,
A switching determination step of repeatedly calculating a drawing processing load for each of the plurality of drawing components;
Each time the drawing processing load is calculated, it is determined whether or not the high-speed buffer is assigned to the highest drawing processing load calculated among the plurality of drawing components. A display switching method comprising: a switching execution step of switching between a drawing component having the highest calculated drawing processing load and a buffer assigned to the drawing component to which the high-speed buffer is assigned.
An integrated circuit that switches a buffer assigned to each of a plurality of drawing components for a high-speed buffer and a general-purpose buffer for drawing an image,
A switching determination unit that repeatedly calculates a drawing processing load for each of the plurality of drawing components;
Each time the drawing processing load is calculated, it is determined whether or not the high-speed buffer is assigned to the highest drawing processing load calculated among the plurality of drawing components. An integrated circuit comprising: a drawing component having the highest drawing processing load calculated; and a switching execution unit that switches a buffer assigned to the drawing component to which the high-speed buffer is assigned.